The president's authorization of domestic
surveillance by the National Security Agency contravened a statute's clear
language. Assuming that urgent facts convinced him that he should proceed
anyway and on his own, what argument convinced him that he lawfully could?

Presumably the argument is that the
president's implied powers as commander in chief, particularly with the nation
under attack and some of the enemy within the gates, are not limited by
statutes. A classified legal brief probably makes an argument akin to one
Attorney General John Ashcroft made in 2002: "The Constitution vests in
the president inherent authority to conduct warrantless intelligence
surveillance (electronic or otherwise) of foreign powers or their agents, and
Congress cannot by statute extinguish that constitutional authority."

Perhaps the brief argues, as its author,
John Yoo - now a professor of law at Berkeley but then a deputy assistant
attorney general - argued 14 days after Sept. 11, 2001, in a memorandum on
"the president's constitutional authority to conduct military operations
against terrorists and nations supporting them," that the president's
constitutional power to take "military actions" is
"plenary." The Oxford English Dictionary defines "plenary"
as "complete, entire, perfect, not deficient in any element or
respect."

The brief should be declassified and
debated, beginning with this question: Who decides which tactics - e.g.,
domestic surveillance - should be considered part of taking "military
actions"?

Without more information than can be
publicly available concerning threats from enemies operating in America, the executive branch
deserves considerable discretion in combating terrorist conspiracies using new
technologies such as cell phones and the Internet. In September 2001, the
president surely had sound reasons for desiring the surveillance capabilities
at issue.

But did he have sound reasons for seizing
them while giving only minimal information to, and having no formal complicity
with, Congress? Perhaps. But Congress, if asked, almost certainly would have
made such modifications of law as the president's plans required. Courts, too,
would have been compliant. After all, on Sept. 14, 2001, Congress had
unanimously declared that "the president has authority under the
Constitution to take action to deter and prevent acts of international
terrorism," and it had authorized "all necessary and appropriate
force" against those involved in Sept. 11 or threatening future attacks.

For more than 500 years - since the rise
of nation-states and parliaments - a preoccupation of Western political thought
has been the problem of defining and confining executive power. The problem is
expressed in the title of a brilliant book, "Taming the Prince: The
Ambivalence of Modern Executive Power," by Harvey Mansfield, Harvard's
conservative.

Particularly in time of war or the threat
of it, government needs concentrated decisiveness - a capacity for swift and
nimble action that legislatures normally cannot manage. But the inescapable
corollary of this need is the danger of arbitrary power.

Modern American conservatism grew in
reaction against the New Deal's creation of the regulatory state, and the
enlargement of the executive branch power that such a state entails. The
intellectual vigor of conservatism was quickened by reaction against the Great
Society and the aggrandizement of the modern presidency by Lyndon Johnson,
whose aspiration was to complete the project begun by Franklin Roosevelt.

Because of what Alexander Hamilton praised
as "energy in the executive," which often drives the growth of
government, for years many conservatives were advocates of congressional
supremacy. There were, they said, reasons why the Founders, having waged a
revolutionary war against overbearing executive power, gave the legislative
branch pride of place in Article I of the Constitution.

One reason was that Congress's
cumbersomeness, which is a function of its fractiousness, is a virtue because
it makes the government slow and difficult to move. But conservatives'
wholesome wariness of presidential power has been a casualty of conservative
presidents winning seven of the past 10 elections.

On the assumption that Congress or a court
would have been cooperative in September 2001, and that the cooperation could
have kept necessary actions clearly lawful without conferring any benefit on
the nation's enemies, the president's decision to authorize the NSA's
surveillance without the complicity of a court or Congress was a mistake.
Perhaps one caused by this administration's almost metabolic urge to keep
Congress unnecessarily distant and hence disgruntled.

Charles
de Gaulle, a profound conservative, said of another such, Otto von Bismarck -
de Gaulle was thinking of Bismarck
not pressing his advantage in 1870 in the Franco-Prussian War - that genius
sometimes consists of knowing when to stop. In peace and in war, but especially
in the latter, presidents have pressed their institutional advantages to expand
their powers to act without Congress. This president might look